Cabochon polishing apparatus



Oct. 18, 1966 c. GIEZENTANNER v3,

CABOCHON POLISHING APPARATUS 4 Sheets-Sheet 1 Filed Dec. 13, 1961 INVENTOR. Charles L. G3ezenronner AT TYS.

Oct. 18., 1966 c. L. GIEZENTANNER 3,279,127

CABOCHON POLISHING APPARATUS Filed Dec. 15, 1961 4 Sheets-Sheet 2 INVENTOR. Charles L. GiezenTunner ATTYS.

Oct. 18, 1966 C. L. GIEZENTANNER CABOGHON POLISHING APPARATUS 4 Sheets-Sheet 5 Filed Dec. 13, 1961 INVENTOR'. Churk-zs L.Giezen#onner BY ATTYS.

Oct. 18, 1966 c, GIEZENTANNER 3,279,127

' cABocHoN POLISHING APPARATUS Filed Dec. 13, 1961 4 Sheets-Sheet 4 INVENTOR. Chafles LGiezenTanner y/$44, AT TYS.

United States Patent 3,279,127 CABOCHON POLISHING APPARATUS Charles L. Giezentanner, 1518 Buell Drive, Moses Lake, Wash. Filed Dec. 13, 1961, Ser. No. 158,988 3 Claims. (Cl. 51-124) -This invention relates to a novel polishing or grinding apparatus for finishing cabochons.

The present invention is designed for use by a rock collector or for professional use. A cabochon or cab is a thin slice of rock on which is formed a smooth radius edge. In amateur practice today, this edge is normally formed by manually holding the rock on a suitable grinding or polishing surface and by turning the rock within ones hand. The rock itself is held on a cylindrical dowel known as dop stick. The cab is secured to one end of the dop stick by dopping wax. The forming of a true radius on the edge of the cab in this manner is both diflicult and time consuming. The present invention is designed about a novel holder for the dop sticks which reduces the time necessary to polish the edge of a cab and further produces a more accurate surface than has been possible heretofore by methods available to amateur collectors.

It is a first object of this invention to provide a novel holder for dop sticks which is usable by amateur collectors without the necessity of precise skill or long experience. A dop stick holder as constructed according to this invention is exceedingly simple in construction and requires no special skills.

Another object of this invention is to provide a mechanical mounting arrangement forthe dop stick holders so as to enable an amateur collector to utilize automatic grindingmethods in polishing and grinding his rock collection. This apparatus is designed as an attachment to existing polishing or grinding wheels which are commonly used by those pursuing this very popular hobby.

These and further objects will be evident from a study of the following disclosure taken in conjunction with the accompanying drawings which illustrate the novel holder and two forms of mechanical mounting apparatus designed particularly for use therewith. It is to be understood at the outset that the mechanical means for holding the dop stick holder are by no means limited to the two forms shown in my drawings. For this reason the invention disclosed herein is to be limited only by the annexed claims.

In the drawings:

FIGURE 1 is a side view of a first embodiment of my invention, showing the grinding apparatus as used and showing the frame of the grinding wheel in section;

FIGURE 2 is a sectional view taken along line 2-2 in FIGURE 1;

FIGURE 3 is an enlarged sectional view taken along line 3-3 in FIGURE 2;

FIGURE 4 is an enlarged view looking at a single mounting assembly along the line 4-4 in FIGURE 2;

FIGURE 5 is a view looking along line 5-5 in FIG- URE 4;

FIGURE 6 is a view similar to FIGURE 1, showing a second form of the mounting apparatus;

FIGURE 7 is an enlarged top view of a portion of the apparatus shown in FIGURE 6;

FIGURE 8 is a sectional view taken along line 8-8 in FIGURE 7; and

FIGURE 9 is a sectional view taken along line 9-9 in FIGURE 8.

The present invention is designed to eliminate the manual manipulation of a dop stick on which is mounted a cabochon or cab for grinding or polishing purposes.

- 3,279,127 Patented Oct. 18, 1966 The basic element of this invention is a holder 10 designed to mount single dop sticks therein. The dop sticks 11 are cylindrical dowels of common construction. These dop sticks 11 are used to mount cabochons or cabs 12 which are thin slices of rock. The cabs 12 are temporarily secured to the sticks 11 by dopping wax 13. One common problem in manual grinding of a cab is the heat generated at the ground surface. If allowed to remain in contact with the grinding or polishing surface for a suflicient time, the cab 12 will be heated to such a degree as to melt the doping wax 13, and thereby ruin the grinding operation.

The holders 10 are constructed in the manner best seen in FIGURE 3. Each holder comprises a cylindrical hollow tube 14 having an intermediate inwardly restricted collar 15 formed therein. One end of the tube 14 is open to receive the dop stick 11, while the other end 16 is closed by a suitable cap or inwardly directed restriction. Between the closed end 16 and the collar 15 are mounted a spring 17 and a ball 18. The ball 18 abuts that end of the spring 17 opposite to the end of spring 17 abutting the closed end 16 of tube 14. Ball 18 acts as a spherical bearing and is designed to compressively abut the end of the dop stick 11 received within the holder 10. Thus a dop stick 11 mounted within the holder 10 is subjected to a compressive force due to the spring 17, but is free to revolve about its axis due to the nature of the ball 18. The holders 10 may be used in a manual fashion by grasping the holders in ones hand and maintaining the cab 12 on a dop stick 11 in contact with a suitable grinding or polishing surface. By adjusting the angle of the holder 10 relative to the surface, one may form an accurate radius about the entire periphery of the cab 12. The small radiusof the cab 12 will cause it to spin at a high rate of speed about its own axis and thereby will provide a cooling current of air which will prevent the wax 13 from being heated above its melting point. The grinding or polishing action will occur due to necessary slippage between the cab 12 and the grinding or polishing surface. In this manner one can very efiiciently polish a smooth radius along the edge of the cab 12 without having .to worry about turning the cab about its central axis. The rate of polishing or grinding is vastly increased over that possible by conventional manual manipulation.

To provide even greater efiiciency a mechanical apparatus for mounting the holders 10 is desirable. One such device is illustrated in FIGURES 1 through 5. The apparatus shown in these drawings is designed to polish eight cabs 12 simultaneously, giving each the same radius edge. Obviously the number of units which may be mounted above a given surface is subject to wide deviations and may be selected according to the necessary requirements of the user.

The conventional portions of this apparatus consist of a polishing wheel 20 which may have an abrasive surface or upon which an abrasive material may be placed for grinding or polishing purposes. The wheel 20 is mounted on a driving shaft 21 which is rotated about its central axis by a driving motor (not shown). The wheel 20 is rotatably supported on a supporting frame 22. Fixed to the frame 22 is a framework 23 mounted on pins 24 which extend through ears 25, formed inwardly from the frame 22. The framework 23 extends over the Wheel 20 at a spaced position parallel to the polishing surface. It ineludes spaced side walls 26, on which are mounted crank arms 27. The identical crank arms 27 are pivotally carried about parallel axes located at identical distances above the polishing surface of wheel 20. The axes of the crank arms 27 are parallel to the upper surf-ace of wheel 20. Mounted on each crank arm 27 is a mounting collar 0 28, designed to be clamped to an individual holder 10 by means of a set screw 29. Each collar is mounted at an identical radial distance from the axis of the crank arm 27 on which it is carried; The pivotal axis of each collar the axis of the associated crank arm 27 in a plane perpendicular to the polishing surface of the wheel 20.

The above mounting arrangement provides a movable pivotal axis for each holder 10. By suitably adjusting the lengths of the crank arms 27 and the positions of the various pivotal axes, it is possible by this arrangement to insure a substantially straight lined motion of the con-. tacted surfaces of the cab 12 and wheel 20. The straight line motion is desirable so as to prevent excessive compressive force being exerted upon a portion of the cab 12 due to the action of spring 17 in the holder 10.

The crank arms 27 are oscillated about their respective axes by means of a rack 31 which is mounted for reciprocation along pins 32 supported between the side Walls 26. The rack 31 meshes with pinions 33 fixed relative to the crank arms 27 on each side of the framework 23. The. rack 31 is reciprocated by a driving crank arm 34 mounted exteriorly of the framework 23 between the framework 23 and wheel 20. Crank arm 34 is moved by an eccentric driving element 35 which is fixed to the central shaft 21 of wheel 20. The rotation ofwheel 20, which is used to polish the cabs 12, therefore results in simultaneous oscillation of each holder mounted in the apparatus. The .holdersl0 are pivotally carried about their movable axes from a perpendicular position shown in full lines in FIGURE 4, to aposition illustrated in dashed lines in FIGURE 4 and to an opposite position which is shown in FIGURE 1. This oscillation will repeat itself continuously during operation of wheel and may be continued until the desired surface is obtained on the cabs 12. The effective radii of the cabs 12 may be adjusted by changing the various links of the pivotal arms supporting the holders 10, or by varying the length of the dop sticks 11 and the position of the framework 23 relative to the fixed supporting frame 22; Such adjustments are well within the skill of the amateur for which this device is designed.

An alternate form of a mechanical device for holding the holders 12 'is shown in FIGURES 6 through 9. In these figures is shown a wheel 36 which is mounted on a supporting frame 37. Mounted above the frame 37 and fixed thereto is a support element 38 having two slotted apertures formed therein in vertical directions and designated by the numerals 39. Each vertical aperture 39 extends longitudinally along a portion of the element 38 at either side of the center thereof.

Mounted centrally with the apertures 39 are U-shaped brackets 40 which extend downwardly therefrom. The U-shaped brackets 40 are fn'ctionaily held against the element 38 by the side plates 41. Thus the elevation of the brackets 40 may be readily varied by loosening the plates 41. Each bracket 40 includes an elongated aperture 42 formed at the bottom thereof. 7

Individual mounting collars 43 are pivotally mounted within each U-shaped bracket 40 by means of supporting pins 44. The collars 43 are designed to be locked against the holders 10 previously described. Thus the collars 43 provide a fixed axis for pivotal movement of the holders 10; The axis of the pins 44 is preferably perpendicular to a radius drawn outwardly from the center of the element 38.

Each holder 10 is oscillated about the axis of pins 44 by means of the central wheel shaft 45 for wheel 36. The shaft 45 is elongated and extends through the element 38. At the top end thereof is formed an eccentric pin 46 which is slidably received within a cross guide 47. The cross guide 47 carries a connecting rod 48 extending out- 4 wardly to each of the holders 10.

to the upper end of the respective holder 10. Thus it may be seen as the shaft 45 rotates about itslcentral ver-r v tical axis the two holders 10 will be oscillated about their pivotal axes in unison.

The wheel 36 in this instance is provided with an an-- nular recess 50 having a channelled radius of the shape desired on the cabs 12. This recess 50 is necessary so as to compensate for the vertical motion of the cab 12 due to movement about the fixed axis of pins 44.: By

relieving the wheel 36, one may effectively compensatefor the arc of the cab 12 being processed. This arrangement is more simple from a structural standpoint than that previously described but requires maintenance of the wheel 36 and the recess 50 for accurate usage.

Many other mechanical devices may be used to mount the holders 10 for polishing purposes. The holders 10.

are usable with a polishing surface such as an endless belt or a wheel mounted about a horizontal axis. Holders. 10 I may also be used within an abrasive cylinder such as are commonly used in the polishing of rocks.

cab against a polishing surface. In a mechanical mounting arrangement it is necessary to provide motion of the holder about an. axis parallel to the contacted polishing surface while also insuring rotation of the cab about. the

central longitudinal axis of the dop stick on which it is mounted.

axes positioned equally distant from said surfaces and parallel thereto;

a plurality of dop stick holders pivotally connected: to said crank arms respectively about axes radially displaced from and parallel to said first named axes;

a plurality of guide collars mounted on said member for pivotal motion about axes parallel to and spaced from said first named axes, the pivotl axes of said guide collars being respectively aligned withsaid first named axes in a plane perpendicular to the moving surface, the separation of said first named axes and the respectively aligned guide collar axes being greater than the radial displacement of the pivotal.

connection of the dop stick holders and the axes of the crank arms on which they are respectively mounted, said guidecollars being adapted to slidably receive the dop stick holder pivotally mountedon the crank arm aligned therewith; and means operatively connected to said crank arms adapted to oscillate said crank'arms about said first named axisin unison.

2. In combination with a continuous moving surface mounted upon a fixed supporting frame, the improvement in an apparatus for forming cabochons comprising:

a holder for a dop stick adapted to maintain a cabochon mounted at the end of a dop stick received therein in compressive tangential engagement with the moving surface;

mounting means on said frame adapted to pivotally carrysaid holder for motion about an axis parallel to the contacted moving surface;

and means on said frame operatively connected to said The outer ends of the 1 connecting rod 48 are connected to a hinged pin 49 fixed The important 1 concept of this invention is the provision of a holder hava ing a spherical bearing which can compressively hold a t in the claims which mounting means adapted to effect said pivotal motion of said mounting means in a continuous cycle; said holder comprising:

a hollow tubular member having an open end adapted to longitudinally receive a dop stick;

compressible resilient means mounted within said member with one end thereof abutting an inwardly projected portion of said member;

and bearing means abutting the remaining end of said compressible means, said bearing means being retained within said tubular member by an inwardly projected portion of said member located between said bearing means and the open end of said member.

3. A holder for a dop stick comprising:

a hollow tubular member having an open end adapted to longitudinally receive a dop stick;

a compression spring mounted within said member with one end thereof abutting an inwardly projected portion of said member;

and a spherical bearing element abutting the remaining end of said compression spring;

said spherical bearing element being retained within said tubular member by an inwardly projected portion of said member located between said spherical bearing element and the open end of said member, said spherical bearing element being adapted to be abutted by the end of a dop stick received within the open end of said hollow tubular member.

References Cited by the Examiner UNITED STATES PATENTS ROBERT C. RIORDON, Primary Examiner.

FRANK A. BRONAUGH, LESTER M. SWINGIJE,

JOHN C. CHRISTIE, Examiners.

I. E. PEEIJE, L. S. SELMAN, Assistant Examiners. 

1. IN COMBINATION WITH A CONTINUOUS MOVING PLANAR SURFACE MOUNTED ON A FIXED SUPPORTING FRAME, THE IMPROVEMENT IN AN APPARATUS FOR FORMING CABOCHONS COMPRISING: A FIXED MEMBER MOUNTED PARALLEL TO AND SPACED FROM SAID SURFACE; A PLURALITY OF IDENTICAL CRANK ARMS PIVOTALLY MOUNTED ON SAID MEMBER ABOUT PARALLEL LONGITUDINALLY SPACED AXES POSITIONED EQUALLY DISTANT FROM SAID SURFACE AND PARALLEL THERETO; A PLURALITY OF DOP STICK HOLDERS PIVOTALLY CONNECTED TO SAID CRANK ARMS RESPECTIVELY ABOUT AXES RADIALLY DISPLACED FROM AND PARALLEL TO SAID FIRST NAMED AXES; A PLURALITY OF GUIDE COLLARS MOUNTED ON SAID MEMBER FOR PIVOTAL MOTION ABOUT AXES PARALLEL TO AND SPACED FROM SAID FIRST NAMED AXES, THE PIVOTAL AXES OF SAID GUIDE COLLARS BEING RESPECTIVELY ALIGNED WITH SAID FIRST NAMED AXES IN A PLANE PERPENDICULAR TO THE MOVING SURFACE, THE SEPARATION OF SAID FIRST NAMED AXES AND THE RESPECTIVELY ALIGNED GUIDE COLLAR AXES BEING GREATER THAN THE RADIAL DISPLACEMENT OF THE PIVOTAL 